题目:分布式通知和协调 参考答案: 对于系统调度来说:操作人员发送通知实际是通过控制台改变某个节点的状态,然后zk将这些变化发送给注册了这个节点的watcher的所有客户端。 对于执行情况汇报:每个工作进程都在某个目录下创建一个临时节点。并携带工作的进度数据,这样汇总的进程可以监控目录……
题目:zk的session机制 参考答案: zookeeper会为每个客户端分配一个session,类似于web服务器一样,用来标识客户端的身份。 session的作用: 客户端标识 超时检查 请求的顺序执行 维护临时节点的生命周期 watcher通知 session的状态: CONNECTING CONNECTED RECONNECTING RECONNECTED CLOSED sessio……
@LiuYongQiang6 目标岗位 本硕均为机电专业相关,比赛和项目也是软硬件结合,个人软开背景中学已经学过pascal和数据结构与算法,大学本科除了C语言和微机原理基本没学过CS相关课程,研究生才把操作系统、组原以及计算机网络补上,顺便补了个c++,抽空玩linux,秋招前3个月开始刷题(牛客300,力……
flutter NoMethodError - undefined method `size' for nil:NilClass错误排查
错误描述: pod install时发生错误 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 ### Error ``` NoMethodError - undefined method `size' for nil:NilClass /Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/macho_file.rb:455:in `populate_mach_header' /Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/macho_file.rb:233:in `populate_fields' /Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/macho_file.rb:55:in `initialize_from_bin' /Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/macho_file.rb:33:in `new_from_bin' /Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/fat_file.rb:365:in `block in populate_machos' /Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/fat_file.rb:364:in `each' /Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/fat_file.rb:364:in `populate_machos' /Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/fat_file.rb:156:in `populate_fields' /Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/fat_file.rb:95:in `initialize' /Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho.rb:31:in `new' /Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho.rb:31:in `open' /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.10.0/lib/cocoapods/xcode/linkage_analyzer.rb:16:in `dynamic_binary?' /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.10.0/lib/cocoapods/sandbox/file_accessor.rb:171:in `block in vendored_dynamic_frameworks' /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.10.0/lib/cocoapods/sandbox/file_accessor.rb:170:in `select' /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.10.0/lib/cocoapods/sandbox/file_accessor.rb:170:in `vendored_dynamic_frameworks' /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.10.0/lib/cocoapods/sandbox/file_accessor.rb:179:in `vendored_static_frameworks' /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.10.0/lib/cocoapods/sandbox/file_accessor.rb:292:in `vendored_static_artifacts' /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.10.0/lib/cocoapods/installer/xcode/target_validator.rb:82:in `each'……
如何使用 Python 基于 PyQt5 第三方库,进行实现 exe 桌面应用软件开发
安装 PyQt5 第三方库开发环境 下面直接使用 pip 来安装 PyQt5,此处可能是 pip/pip3,或者两者皆可,后面不再重复 直接 pip 安装 PyQt5,当然也可以加镜像加快安装 pip install PyQt5 由于 Qt Designer 已经在 Python3.5 版本从 PyQt5 转移到了 tools,因此我们还需要安装 pyqt5-tools pip install pyqt5-tools 然后键盘按下 Win+S 呼出 Cornata 主面板(搜索框),输入 desi……